Patch "net: sctp: fix memory leak in auth key management" has been added to the 3.10-stable tree

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This is a note to let you know that I've just added the patch titled

    net: sctp: fix memory leak in auth key management

to the 3.10-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     net-sctp-fix-memory-leak-in-auth-key-management.patch
and it can be found in the queue-3.10 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.


>From foo@baz Tue Nov 18 09:07:46 PST 2014
From: Daniel Borkmann <dborkman@xxxxxxxxxx>
Date: Mon, 10 Nov 2014 18:00:09 +0100
Subject: net: sctp: fix memory leak in auth key management

From: Daniel Borkmann <dborkman@xxxxxxxxxx>

[ Upstream commit 4184b2a79a7612a9272ce20d639934584a1f3786 ]

A very minimal and simple user space application allocating an SCTP
socket, setting SCTP_AUTH_KEY setsockopt(2) on it and then closing
the socket again will leak the memory containing the authentication
key from user space:

unreferenced object 0xffff8800837047c0 (size 16):
  comm "a.out", pid 2789, jiffies 4296954322 (age 192.258s)
  hex dump (first 16 bytes):
    01 00 00 00 04 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace:
    [<ffffffff816d7e8e>] kmemleak_alloc+0x4e/0xb0
    [<ffffffff811c88d8>] __kmalloc+0xe8/0x270
    [<ffffffffa0870c23>] sctp_auth_create_key+0x23/0x50 [sctp]
    [<ffffffffa08718b1>] sctp_auth_set_key+0xa1/0x140 [sctp]
    [<ffffffffa086b383>] sctp_setsockopt+0xd03/0x1180 [sctp]
    [<ffffffff815bfd94>] sock_common_setsockopt+0x14/0x20
    [<ffffffff815beb61>] SyS_setsockopt+0x71/0xd0
    [<ffffffff816e58a9>] system_call_fastpath+0x12/0x17
    [<ffffffffffffffff>] 0xffffffffffffffff

This is bad because of two things, we can bring down a machine from
user space when auth_enable=1, but also we would leave security sensitive
keying material in memory without clearing it after use. The issue is
that sctp_auth_create_key() already sets the refcount to 1, but after
allocation sctp_auth_set_key() does an additional refcount on it, and
thus leaving it around when we free the socket.

Fixes: 65b07e5d0d0 ("[SCTP]: API updates to suport SCTP-AUTH extensions.")
Signed-off-by: Daniel Borkmann <dborkman@xxxxxxxxxx>
Cc: Vlad Yasevich <vyasevich@xxxxxxxxx>
Acked-by: Neil Horman <nhorman@xxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 net/sctp/auth.c |    2 --
 1 file changed, 2 deletions(-)

--- a/net/sctp/auth.c
+++ b/net/sctp/auth.c
@@ -874,8 +874,6 @@ int sctp_auth_set_key(struct sctp_endpoi
 		list_add(&cur_key->key_list, sh_keys);
 
 	cur_key->key = key;
-	sctp_auth_key_hold(key);
-
 	return 0;
 nomem:
 	if (!replace)


Patches currently in stable-queue which might be from dborkman@xxxxxxxxxx are

queue-3.10/net-sctp-fix-memory-leak-in-auth-key-management.patch
queue-3.10/net-sctp-fix-null-pointer-dereference-in-af-from_addr_param-on-malformed-packet.patch
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